A definite need exists for a more reliable, simplified and more economical mechanism for shutting down diesel engines and the like immediately in the event of a serious engine malfunction. Devices for this purpose are known in the prior art but have not proven to be entirely satisfactory due to excessive complexity and cost, too many parts employed, and instability of the mechanism under heavy vibration. Examples of the patented prior art are shown in U.S. Pat. Nos. 2,096,291; 2,551,429; 2,706,025 and 2,854,964.
The objective of the invention, therefore, is to provide a more simplified and reliable device or mechanism for shutting down engines responsive to an engine malfunction. In accordance with the invention, the device employs a significantly reduced number of parts which are sturdy in construction and simplified as to operation and very reliable. Excessive vibration will not cause premature release of the mechanical latch means nor interfere with the resetting thereof manually. The device employs a manual linear reset rod or plunger which directly carries the armature of a solenoid which is used to hold the mechanism in an engine "on" position against the opposing force of a spring which constantly biases the mechanism to the engine "off" or shut-down position. The simple vibration-proof latch mechanism associated with the reset rod and solenoid allows the device to be installed in any position without dependency on gravity.
Following any interruption of power to the coil of the solenoid, spring force returns the reset rod immediately to the engine shut-down position, thus rendering the device electrically fail-safe.
Other features and advantages of the invention will become apparent during the course of the following description.